Power and Trim Estimation for Helicopter Sizing and Performance Analysis

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International Journal of Aeronautical and Space Sciences, Volume 12, Number 2, p.156–162 (2011)

Abstract:

The preliminary design stage of helicopters consists of various operations and in each operation design several detailed analysis&nbsp;tasks are needed. The analysis tasks include performance and the required power estimation. In helicopter design, those are&nbsp;usually carried out by adopting the momentum theory. In this paper, an explicit form of computational analysis based on the&nbsp;blade element theory and uniform/non-uniform inflow model is developed. The other motivation of the present development&nbsp;is to obtain trim and required power estimation for various helicopter configurations. Sectional and hub loads, power, trim, and&nbsp;flapping equations are derived by using a symbolic tool. Iterative computations are carried out till convergence is achieved in&nbsp;the blade response, inflow, and trim. The predictions regarding the trim and power estimation turn out to be correlated well with&nbsp;the experimental results. The effect of inflow is further investigated. It is found that the present prediction for the lateral cyclic&nbsp;pitch angle is improved with the non-uniform inflow model as compared to that by the uniform inflow model. The presently&nbsp;improved trim and power estimation will be useful for future helicopter sizing and performance analysis.